Hi Phil,

Well spotted! Yes, I was riding on the CC40C for all the climbs and descents. From experience you have to be very careful with full carbon clinchers that you may not know the development or testing process that they have been through. You and your tour operator are right to be concerned as resins can easily melt under extended braking which can lead to a serious catastrophe. On the outside carbon can look the same but dig a bit deeper and it’s very different underneath. With this in mind I would not ride any carbon clinchers in the mountains that have not been extensively tested and can prove their performance in this application. Mavic spent over 2 years developing the Cosmic Carbon 40 wheel which was tested extensively in the lab and on Mont Ventoux (with a 100kg rider dragging the brakes the whole way down) to validate their materials. They use two types of high temperature resin and a thin internal aluminium rim to dissipate heat build up and also improve braking consistency. This is the only carbon clincher I would trust (I’ve done a huge amount of mountain miles on them last year).

My advice would be, if you have any doubt whatsoever in your equipment then think again about using it in the high mountains.

Super happy that you’re enjoying The Col Collective. Much more to come!

Ride safe,

Mike

The carbon spokes on the R-Sys SLR are absolutely capable of standing the cobbles but the overall design of the wheel makes it not the best for this particular event due to its high stiffness. A set of Ksyrium SLS wheels would bring more compliance, control and comfort, however the tyre for this ride is really the key element. It’s a real shame that you can’t use wider than 25mm as this would bring you a lot of added comfort, grip, safety and ride quality needed on the cobbles.

Thanks for your support, good luck!

Mavic

Hi Edson,

That is a great question and one that needs to be taken very seriously indeed. You’re right to be concerned about rims potentially overheating and compromised braking performance in the wet. In some cases event organisers have gone to the extent of forbidding the use of carbon clinchers where they feel that the overheating may be an issue. We released our Cosmic Carbone 40 Clincher (CC40C) in Spring 2013 after over two years of extensive development and testing to ensure that both of these criteria were met and that rider safety was in no way an issue whatever the conditions. The CC40C utilises a very light weight internal aluminium rim bed that not only dissipates heat but also ensures that the brake track is perfectly true to prevent a rim that feels like it pulses under braking conditions. We developed several types of high temperature resins (TgMax Technology) to ensure that the CC40C achieves the highest possible resistance to braking heat. Not only was this tested in the lab but we also undertook an extensive analysis out in the field with a 100kg rider descending Mont Ventoux whilst dragging the brakes continuously for over 10km. We were also able to reduce stopping distance in the wet by over two times when compared to other carbon rims.

The unfortunate thing is that on the surface carbon can look the same, whereas underneath the surface it is very, very, different. If you are not confident in the materials and testing that your wheels have under gone (or you can’t find out) then we would seriously consider not using them in very mountainous events like the Etape du Tour. We can’t answer for every manufacture but we can say that if you are using a CC40C then we are confident in the performance of this wheel for mountain riding.

We hope that helps. Best of luck next July in the Alps!

Mavic